Thread: Industrial Meths

I think it might all be a bit of a labelling con. The following IMS's both allow water (see under ingredients)

http://www.langridgecolours.com/pdf/100%25MethsMSDS.pdf
http://www.diggersaust.com.au/files/...rits%20100.pdf

The 100% is specified at a particular atmosheric pressure and temperature under controlled conditions. It seems to me that regular metho could comply with these.

It might be best not to rely on the label but do Astrids test. Metho is hydroscopic and miscible in water. Anhydrous just means that at the testing time and under test conditions it did not contain any water (o.3% maximum according to BP specs http://www.distill.com/specs/BPChemicals5.html).

As soon as you open the bottle it will start to absorb water from the atmosphere. If you buy a big drum, as soon as you decant some and let air in it will absorb water from the atmoshere. You cannot change the properties of a hydroscopic fluid by adding something. Even if you could it would be no longer 100% meths. The MDS also state that it is completely miscible so it obviously absorbs water.

I agee, just my adding methonal alone, which is poisonious to the ethonol will denature it.

There are many other solvents that can be added to the ethyl alcohol to make it not fit to drink for human comsumtion, but still usable for other usuages in finishing. All ethyl alcohol is taxable that was the reason to denature the alcohol, so they would not loss the taxes on the drinking kinds..

Alcohol, does not remain on the pieces of furniture, because it evaporated, so it should not be taxable.

Originally Posted by Pusser

... but do Astrids test. ...

I think you mean Wendy's - putting some meths in a bottle with turps and shaking....

Since the thread has been ressurected.... I got 100% ethanol from a car detailing supplies place in Penrith. He also sells top end spray equipment and higher grades of wet and dry.

Great tip Astrid!

Sebastiaan

Originally Posted by jmk89

I think you mean Wendy's - putting some meths in a bottle with turps and shaking....

Yes sorry for the mix up.

The best part about buying 100% IMS is that you are starting with virtually no water in the alcohol and the good stuff (what we use for our polishes) only has 0.05% denaturant so it is as close as possible to pure alcohol.

95% IMS is also acceptable in most instances, unmarked (no percentage) isn't acceptable as there is no law prohibiting the addition of water to the mix so long as the alcohol is still OP (Over Proof) which means it will burn if a flame is put to it. Metho will still burn with around 47% water in it. It won't dissolve shellac and if used to thin premixed polish will go cloudy and will bloom (look milky) on the surface.

As above: 100% IMS is basically water free - Yes it will absorb water from the atmosphere, but even if left unopened in a really humid area for a few week it wouldn't absorb all that much water to make it more than 95%..... The alcohol will evaporate off but still won't have that much water in it.

However, (and here's the weird part) the regulations here in OZ say that 95% can contain as much as 20% or more water, even 100% can have as much as 5%. It's all very confusing, but rest assured..... If you use 100% and you have good shellac it will always dissolve.

There's no guarantee of that with any of the other alcohols sold here in OZ. I have seen shellac go into a gluggy mess when mixed with one of the so called better brands of 95%, where the same shellac dissolved beautifully in 100% within 15 -20 minutes.

If your shellac hasn't dissolved within 30 minutes there is a bit of a problem if it hasn't dissolver within 1 hour throw it out and get some good metho or fresh shellac. There will always be a little sediment in the mix that needs to be strained out but that's ok. The bulk of it should be liquid within 30 minutes to an hour.

Cheers - Neil

Thanks Neil,

It is more confusing when you look at the MDS's . The Langridge colours 100% meths allows up to 10% water while diggers allows up to 4.2%. These are specifiied by proportion not by volume or mass which allows for even more variability.

The European BP specification allows .5% water by mass whereas the % meths is by volume.

It leaves me to the conclusion that you need to test each batch - You could have 95% of one brand with less water than 100% of another brand!?